An acoustic signal from a distance sound source in an enclosed space produces reverberant sound that varies depending on the room impulse response (RIR). The estimation of the quality of human speech in an observed signal in light of the level of reverberation in the space provides valuable information. For example, in typical speech communication systems such as voice over Internet protocol (VOIP) systems, video conferencing systems, hands-free telephones, voice-controlled systems and hearing aids, it is advantageous to know if the speech is intelligible in the signal produced despite the room reverberation.